safety of genetically modified (gm) nufs 427 fall 14
TRANSCRIPT
SAFETY OF GENETICALLY MODIFIED (GM) FOOD
NUFS 427/ AFNS 527 October 2, 2014
1
Ka#e Satchwell Dr. Chris#ne Liu
2
How many of you think GM foods are unsafe?
What does it mean to “genetically modify”?
“To change the heritable traits of a plant, animal or microorganism by means of intentional manipulation”
Food and Drug Regulations B28.001
3
Genetically modified organisms (GMOs) • Organisms with their DNA modified through genetic
engineering techniques
…in a way that does not occur naturally by mating and/or natural recombination (EUROPEAN COMMISSION DIRECTORATE-Directive 2001/18/EC Article 2)
4
Genetic modification (GM) • During GM process, DNA is modified:
– deletion of genes – addition of genes – transgenic (from a different host)
5
Controversies with Biotech • Voluntariness: Need for choice/consent • Risk/Benefit distribution/equity issues/social fairness • Fear/dread/safety/catastrophic potential • Distrust: Challenging motivations/knowledge of
stakeholders
6
AgBioTechNet. 2004. [6] ABN 128:1-8.
Controversies with Biotech • Ethics/morality of Biotechnology (GM) technologies • End uses of Biotech • Motivations:
• Reason for GM/Biotech • Type of organism to be modified • Source of different gene • History of use • Containment
7
AgBioTechNet. 2004. [6] ABN 128:1-8.
Demand for GMO’s : Potential Benefits
• Better or different products • Reduced wastage
• Whole plant utilization
• Enhanced nutrition • Biodegradable plastics • Health benefits –
“Nutraceuticals” • Vaccine delivery • Pharmaceuticals • Natural dyes
• Abundance for all • Abiotic stress resistance
• nitrogen use efficiency • Cold tolerance • Heat tolerance • Drought tolerance
• Reduced Pesticides
8
• Pharmaceutical: • human insulin gene inserted into Escherichia coli (Herbert Boyer,
1978)
• Vaccine delivery: • Oral vaccination with GM Lactobacillus acidophilus expressing the
protective antigen against Bacillus anthracis
“Mucosal vaccination and therapy with genetically modified lactic acid bacteria”
Wells J, 2011. Annu Rev Food Sci Technol. 2:423-445.
• Food: • production of chymosin by GM yeast for clotting of milk during cheese-
making
• Plants: • biodegradable plastic produced by GM plants or microorganisms • insect resistant (Bt) crops • herbicide tolerant (Ht) crops • “golden rice” with β-carotene
9
Direct consumer benefits • Availability of fresh or abundant food
• Desirable functional properties
• Reduced allergenicity Peanut proteins
Dairy starter cultures – stabilization of acid production, proteolytic activity, citrate utilization
– resistance to phage Meat and vegetable starter cultures
– rate of acid production – production of inhibitory substances
10
Direct consumer benefits- Chymosin Chymosin (also known as rennin) is the primary active ingredient in
rennet. • essential to the manufacture of firm cheeses. • Chymosin splits the casein protein of milk at specific point and
thereby effects clotting: casein clumps together to form curd and separates from the whey.
• Subsequently, the ripening process of cheese may begin. Application: • Chymosin is used exclusively in the manufacture of cheese, Rennet is
obtained from frozen calf stomach using an acid extraction • The demand for cheese can not be met by traditional rennet. • A large part of global cheese production is conducted using GM
chymosin. • http://www.gmo-compass.org/eng/database/food/245.cheese.html
11
Chymosin production: using Biotech Chymosin gene isolated from calf stomach transferred to appropriate producer organisms, such as bacteria, moulds or yeasts.
Organism allowed to multiply and cultivated in a closed system (fermenter), in which they release chymosin into the culture liquid.
Chymosin is separated and is cleaned of possible impurities including cell debris from the GM microorganisms.
A variety of chymosin products are on the market and include Chy-Max (made with Aspergillus niger) or Maxiren (Kluyveromyces lactis; yeasts).
Chymosin produced with GM microorganisms consists of 80 to 90 % active ingredient and is significantly purer than natural rennet, which contains only between 4-8% active chymosin.
12
Nutritionists discuss the merits of biotechnology - Institute of Food Technology, 2013
• “Bt (insect resistant) crops produce higher yields, reduce the use of insecticide, and are not toxic to humans and other animals”
• “The benefits of Ht (herbicide tolerant) crops are reduced labour costs, reduced tillage of soil, and reduced soil erosion”
• “Bt and Ht crops are in widespread cultivation, and while affluent nations can afford to grow and purchase only organically grown plant foods, poor, malnourished populations in developing regions cannot”
14
http://futurefood2050.com/futurist-stewart-brand-is-betting-on-biotech/
Golden rice • developed to address Vitamin A deficiency especially
among children (Philippine Rice Research Institute)
• will be available on the Philippine market by 2015 (Manila Standard Today, 2013-10-31)
15
daniellelevynutrition.com
GM foods in Canada
16
17
Source: US Department of Agriculture
18
• RNA interference was used to block the expression of the milk protein - β-lactoglobulin, which causes allergy
Are GM Foods Safe? Institute of Food Technologists, 2000
• recombinant technology…. will benefit consumers, farmers and the environment
• safety of food derived from GMOs is adequately assured
• risks to environment are no different than those of plants bred by traditional methods
19
Concerns raised about the safety of GM foods
• The inserted gene may
• alter the behaviour of a microorganism, which is carrying it to make it potentially harmful
• be transferred from one microorganism to others, in the human gut or respiratory tract or to animals or humans
• The consumption of a GM microorganism may
• alter the balance of existing microorganisms in the human gut
20
DEBATE: SAFETY OF GM SALMON
21
Background - AquAdvantage® salmon (AquaBounty Tech.)
22
Promoter of an7freeze gene from Ocean Pout
Growth hormone gene from Chinook salmon
Fer7lized egg of Altan7c salmon
GM salmon
Bodnar, 2010. Risk assessment and mi#ga#on of AquAdvantage salmon.
Claims on GM salmon by the public
23
• Overexpression of growth hormones (GH)
• “Spreading of the GM gene to the environment”
Risk assessment and mitigation of AquAdvantage salmon
– Anastasia Bodnar, 2010. Biology Fortified.
http://www.biofortified.org/2010/10/salmon/
24
GM salmon • In the article, risk assessment was performed:
• the science behind the salmon • animal growth, health, and welfare • preventing escape • biological containment • physical containment • environmental containment • human health
25
Growth hormone • GH of lower vertebrates do not bind the Growth Hormone Receptor (GHR) of higher vertebrates à no effects on humans
• Salmon over expressing GH under wild conditions have decreased swimming speed à higher death rates due to the decreased ability to swim away from predators and decreased ability to catch prey (Hu W, & Zhu Z, 2010. Life sci, 53:401-8)
26
Containment of GM salmon • “Because all farmed salmon have reduced ability to
survive in the wild, and 98% or more of AquAdvantage salmon are sterile, the likelihood of escaped animals interfering with the natural ecosystem, becoming established in the environment, or breeding with sexually compatible fish nearby is extremely small.”
27
Bodnar A, 2010
IN-DEPTH REVIEWS ON THE SAFETY OF GM FOODS
28
An overview of the last 10 years of genetically engineered
crop safety research (Nicolia et al., 2013. Crit. Rev. Biotechnol.)
29
Review of GM crops • Interaction of GE crops with the environment
• Interaction of GE crops with humans and animals
• GE food/feed consumption
• Traceability
30
GM genes to the environment
• gene flow is not unique to GM technology and is commonly seen in wild plants and non-GM crops
31
Safety of ingesting transgenic DNA • enormously diluted—where it remains in food at all
• transgenic DNA does not differ intrinsically or physically from any other DNA already present in foods
• no evidence to suggest that recombinant DNA would be processed in the gut in any manner different from endogenous feed-ingested genetic material (Sharma et al., 2006. J. Agric. Food Chem. 54:1699-1709)
• the ingestion of transgenic DNA does not imply higher risks than ingestion of any other type of DNA (European Commission, 2010)
32
Traceability: detect GM genes • PCR targeting transgenes of GM plants:
• insect-resistant gene: cry1Ab • antibiotic resistant genes: Hph (hygromycin
phosphotransferase) and NptII (neomycin phosphotransferase)
• virus promoters: Cauliflower Mosaic Virus 35S promoter* (p-35S) and Figwort Mosaic Virus 35S promoter (p-FMV)
33
Cottenet et al., 2013. Anal. Bioanal. Chem. 405:6831-44.
p-35S promoter from virus • used to drive the expression of transgenes in genetically
modified plants
• sequence overlap between P35S and viral gene VI - encoding the multifunctional P6 protein*
• concerns of the expression of functional domains of the P6 protein in transgenic plants
• in silico analysis showed no relevant similarity was identified between the translation products of gene VI overlapping P35S and known allergens and toxins in humans or animals
34
Podevin & du Jardin. 2012. GM Crops Food. 3:296-300.
*P6: involved in the infectious cycle of the virus
REGULATION OF GM FOODS
35
36
J. Consumer Protection and Food Safety. 2014. 9 (Suppl 1): S51-S58
Regulation of GM Foods Health Canada - Novel Food Regulations Novel Foods are:
• Foods resulting from a process not previously used for food
• Products that do not have a history of safe use as a food • Foods that have been modified by genetic manipulation,
also known as genetically modified foods, GM foods, genetically engineered foods or biotechnology-derived foods
37
*
Health Canada Approved Foods http://www.hc-sc.gc.ca/fn-an/gmf-agm/appro/index-eng.php
• Although these foods are approved, they may or may not be for sale currently
• The regulation of novel foods in Canada (including GM foods) and the safety assessment process are similar to the international standards by: • World Health Organization
(WHO) • Food and Agriculture
Organization (FAO) of the United Nations
• Organization for Economic Co-operation and Development (OECD)
38
TWO concepts of regulation on GM foods
Precautionary principle
• EU
Substantial equivalence
• Canada • United States
39
Precautionary principle
Precaution – the “precautionary principle” or “precautionary approach” – is a response to uncertainty, in the face of risks to health or the environment. In general, it involves acting to avoid serious or irreversible potential harm, despite lack of scientific certainty as to the likelihood, magnitude, or causation of that harm.
In the absence of evidence of safety, no approval
Can you prove the harm does not exist?
40
Labeling GMO in EU • Starting from 2004, all food products that make direct use
of GMOs at any point in their production are subjected to labeling requirements, regardless of whether or not GM content is detectable in the end product
41
http://www.gmo-compass.org/eng/regulation/labelling/93.new_labelling_laws_gm_products_eu.html
Substantial equivalence
• a genetically modified plant, or food derived there from, is equivalent to their conventional counterparts
• can be treated in the same manner with respect to safety as their conventional counterparts. -FAO
42
Risk Assessment for Biotech Products
Substantial equivalence
– science-based approach
– GM food is compared to its existing counterpart
Does genetic modification result in food that is inherently less safe than that produced by conventional means?
43
Labeling? • Label GM, so consumers
can have a choice • Label non-GM, so
consumers can have a choice
44
www.gohappy.com.tw
www.snackingsquirrel.com
Food Navigator: vote on an initiative (I-522) calling for mandatory GMO labeling
45
Based on the title of this article, one would believe GM soy is more unsafe than conventional soy…
Article abstract 46
Food Chem. 2014. 153: 207.215.
A closer look…the hypothesis:
47
Food Chem. 2014. 153: 207-215.
A closer look…Study Design: • 31 samples (3kg) of soybeans tested from 200 km radius from
Iowa n=10 GM; n=10 conventional; n=11 organic
• Nutritional composition of soybeans: total protein, total fat dry matter, starch, ash, minerals, trace elements, vitamin B6, Amino acid and fatty acid composition
• Residues of glyphosate (Roundup) and AMPA (aminomethylphosphonic acid) screened using HPLC by Eurofin laboratories
• Data analyzed using multivariate analyses: one-way ANOVA
48
Food Chem. 2014. 153: 207-215.
Results 49
-Authors fail to mention detection limit of method used to detect residues -Pesticide residues are regularly found in conventional and organic produce -the EPA conducted a risk assessment of glyphosate and concluded that chronic dietary risk posed for food uses is minimal -A reference dose (RfD) based on daily exposure that would not cause adverse effects throughout a lifetime is 2mg/kg/d
EPA R.E.D. Facts sheet. 1993. Glyphosate. EPA-738-F-93-011. http://www.epa.gov/oppsrrd1/REDs/factsheets/0178fact.pdf
Food Chem. 2014. 153: 207-215.
68 kg individual would need to consume 34 kg of “GM-soy” per day to reach any level that would cause adverse effects
Results cont.
50
Is the difference that significant??
Food Chem. 2014. 153: 207-215.
Issues with this study • Sample size is too small for statistical significance
• Authors fail to discuss detection limits of residues
• Claims made are not supported by data
• None of the merits studied discuss the SAFETY of the use of biotechnology
• Are glyphosate/AMPA really a concern? • Sensationalizing of the issue
51
Summary • Genetic recombination is a common phenomenon in
nature
• GM foods are safe as long as the manufacturing processes are strictly regulated
• Need to educate the general public
52
GMO’s : the debate • Potential Concerns :
• “Against nature” • Environmental risk • “Superweeds”
• Invasive species creation • Gene transfer from crops to their wild relatives
• Food safety – toxins? • In the hands of a few (anti-globalization)
53
54
“You people in the developed world are certainly free to debate the merits of genetically modified foods, but can we please eat first?”
Florence Wambugu (2003) CEO, Africa Harvest
55
• Florence Wambugu is an agricultural plant pathologist who is dedicated to increase the food production in Africa using biotechnology
Communicate with public audiences • How to educate public audience/consumers?
• Scientific facts vs. personal opinions
• Challenge remains
56
What are your three messages for consumers?
57
Further Information Health Canada
www.hc-sc.gc.ca/fn-an/gmf-agm/index-eng.php FDA Risk assessment
http://www.fda.gov/cvm/CloneRiskAssessment_Final.htm Food and Agriculture Organization of the United Nations www.fao.org http://www.fao.org/DOCREP/006/Y5316E/Y5316E00.HTM
58